Solenoid-type electromagnetic relays



April 1963 o. M. ULBING 3,088,011

SOLENOID-TYPE ELECTROMAGNETIC RELAYS Filed Dec. 16, 1959 H6 7 INVENTOR. OTTM AR M. ULB me ATTORNEY United States Patent 3,088,011 SOLENOID-TYPE ELECTROMAGNETIC RELAYS Otmar M. Ulbing, Berkshire, N.Y., assignor to Winatic Corporation, Vestal, N.Y., a corporation of New York Filed Dec. 16, 1959, Ser. No. 860,031 2 Claims. (Cl. 200-111) This invention relates to electromagnetic relays and, more particularly, to relays of the solenoid actuated armature type.

Conventional relays, in a wide variety of forms, generally employ spring contactors actuated by a lever attached to a soft iron armature which is attracted to the core of a winding by the magnetic flux generated when the winding is energized. While such relays are simple to construct, and may use any number of contact elements, they have certain distinct disadvantages. The contact springs being resilient may vibrate upon shock excitation causing an undesired operation. The contact points afiixed to the springs have to be closely spaced and since their motion is substantially perpendicular to the surface, oxidation due to arcing presents a conductivity problem. Theelastic collision of the metal contacts often causes also bouncing at a certain repetition rate of closure. The open contact structure may accumulate dust and dirt between the contact points and, for this reason, such relays must be protected by a dust-proof cover.

It is a primary object of this invention to provide a relay which while extremely simple in construction, eliminates all of the above disadvantages.

It is a particular feature of this invention that a relay constructed in accordance therewith is completely enclosed and is shock-proof in operation.

Other objects and features will be apparent from the following description of the invention, pointed out in particularly in the appended claims, and taken in connection with the accompanying drawing, in which:

FIGURE 1 is a cross-sectional view of the relay assembly with the armature in closed position;

FIGURE 2 is a sectional view taken along lines AA of FIGURE 1;

FIGURE 3 is a view of the relay partially cut away showing the armature in open position;

FIGURE 4 shows the contact ring;

FIGURE 5 is a side view thereof;

FIGURE 6 shows the contact ring in an ofiset position;

FIGURE 7 is a modified form of the relay; and

FIGURE 8 is a view taken along lines B--B of FIG- URE 6.

Essentially, the relay, in accordance with this invention, consists of a magnetic field producing winding, and an armature in the form of a ferromagnetic plunger coaxially disposed with respect to the winding, and adapted to be moved inwardly thereof, upon creation of a magnetic field due to current flow in the winding. The plunger has a cylindrical contact carrying head which supports in a peripheral groove an open-ended contact ring. A stationary support surrounds the head of the armature in which the latter moves as a piston. Im'bedded in this support are strategically placed contact elements, which engage the contact ring upon actuation of the armature.

Referring to the drawings, as seen in the sectional view of FIGURE 1, the relay consists in its main operating parts of a solenoid formed by the winding 10* which is supported on a bobbin 11, preferably of molded plastic material. Coaxially with the bobbin 11 and slidable therein is the soft iron plunger 13 having a stem 14.

3,088,111 1 Patented Apr. 30, 1963 Placed on the stem 14 and securely fitted thereon is the contact carrying head 15.

In the preferred embodiment shown in FIGURES l, 2 and 3, the head 15 is of cylindrical cross section and has an inner concentric channel 17 which houses the spring 18. The latter abutting against the side 19 of the bobbin 11 resiliently supports the plunger 13 in a position extending from the center of the winding 10 when the latter is de-energized. The head 15 carries a peripheral groove 21 in which is placed the open-ended contact ring 22. The groove 21 is so dimensioned that the contact ring 22 is free to rotate and also has axial freedom. In its expanded position, the ring 22 has a larger diameter than the head 15.

The construction of the contact ring 22 is illustrated in FIGURES 5 and 6. It is seen that it resembles a piston ring as used in internal combustion engines, being open-ended by the diagonally cut slot 23. The ring 22 may be made of various spring materials such as Phosphor bronze or steel and silver plated for high electrical conductivity.

In certain applications where the ambient frequency of the relay installation is such as to adversely affect the contact making properties of the ring 22, the latter may be made self locking. This is accomplished by offsetting the ring 22 as seen in FIGURE 6. Pressing against the contacts 32 and 33, the offset ring is forced to close against the edges where it is split and bouncing is thereby prevented. During transfer, the ring is unlocked by the pressure exerted upon it by the sides of the peripheral groove.

The casing 25 of the relay is a cylindrical body of insulating material having a cavity at one end which accommodates the bobbin 11. The latter is held therein by the plate 26, which snaps in place under the flanged end 27 of the casing 25. A threaded stud 28 imbedded in the disc 26 serves as a mounting means for the relay. A ring 30 held by the stud 28 serves as a mounting spacer.

The top portion of the casing 25 represents a solid block 31 having a cylindrical opening, the walls of which surround the head 15 and in which the latter may slide freely. A number of contact elements may be arranged in the block 31 such as 32, 33 and 34, as seen in FIG- URE 2, which are placed so as to tangentially engage the ring 22. These contact elements may be molded in the block 31 inasmuch as the casing 25 and the block 31 are preferably made of one piece molded insulating material of phenolic or other well-known resins.

One of the contact elements such as 32 is so positioned as to engage the ring 22 in both the open and closed positions, thereby becoming the common contact element of the relay. The other contacts are so placed as to be free from engagement with the ring 22 when the relay is dc-energized as seen in FIGURE 3.

The operation of the relay is self-evident from the above description and illustrations. When the winding 10 is de-energized, the head 15 is held by the spring 18 against the wall 36 of the block 31. The plunger 13 is in a position extending from the center of the winding 10. The ring 22 engages only the contact element 32. Upon current flow, in the winding 10', the plunger 13 is pulled in and the head 15 moves so that the ring 22 completes the electrical connection between contact element 32 and the other contacts 33 and 34. In the example illustrated, the action is that of a two-circuit, single-pole, single-throw relay. Obviously, by different placement of the contact elements, a variety of combinations may be made for closing or opening circuits in both positions of the head 15.

It is readily seen that the operation results in a positive contact between all elements. The wide linear spacing head 15 of which each surface may support a contact plate. In the illustration, the head 15 is hexagonal and carries contact plates 36, 37 and 38, which overlap adjacent sides of the hexagon. The block 31 has, of course, a hexagonal cutout to slidably accommodate the head 15. Each inner wall of the cutout may have a contact element 40, 41, 42, 43, 44 and 45 which are bridged by the respective contact plates 36, 37 and 38, as seen in FIGURE 7. As illustrated, this modification represents a three-circuit, single-pole, single-throw relay. Various combinations may be effected by judicial placernent of the contact plates carried by the head 15 and corresponding contact elements in the block 31.

I claim:

1. In an electromagnetic relay of the solenoid type having a magnetic field producing winding, a ferromagnetic plunger coaxially disposed with respect to said winding and adapted to be moved inwardly thereof upon creation of a magnetic field due to current flow in said Winding, means for resiliently supporting said plunger in a position extending from the center of said field, a cylindrical contact carrying head of insulating material attached to said plunger, said head having at least one peripheral groove, a current conductive ring rotatably supported in said groove, a stationary support surrounding said head, said support having at least two contact elements adapted to engage tangentially the peripheral side of said ring upon inward movement of said plunger, said current-conductive ring being open ended having a diagonally-cut slot and adapted to be compressed upon engaging said contact elements.

2. An electromagnetic relay in accordance with claim 1, wherein said ring is offset and adapted to be locked upon being constrained by engagement with said contact elements.

References Cited in the file of this patent UNITED STATES PATENTS 1,674,052 McLaughlin June 19, 1928 1,928,846 Allen Oct. 3, 1933 2,189,190 :Blum Feb. 6, 1940 2,198,659 DeVincenzi Apr. 30, 1940 2,323,389 Frei July 6, 1943 2,454,342 Ross Nov. 23, 1948 2,586,750 Wagner Feb. 19, 1952 

1. IN AN ELECTROMAGNETIC RELAY OF THE SOLENOID TYPE HAVING A MAGNETIC FIELD PRODUCING WINDING, A FERROMAGNETIC PLUNGER COAXIALLY DISPOSED WITH RESPECT TO SAID WINDING AND ADAPTED TO BE MOVED INWARDLY THEREOF UPON CREATION OF A MAGNETIC FIELD DUE TO CURRENT FLOW IN SAID WINDING, MEANS FOR RESILIENTLY SUPPORTING SAID PLUNGER IN A POSITION EXTENDING FROM THE CENTER OF SAID FIELD, A CYLINDRICAL CONTACT CARRYING HEAD OF INSULATING MATERIAL ATTACHED TO SAID PLUNGER, SAID HEAD HAVING AT LEAST ONE PERIPHERAL GROOVE, A CURRENT CONDUCTIVE RING ROTATABLY SUPPORTED IN SAID GROOVE, A STATIONARY SUPPORT SURROUNDING SAID HEAD, SAID SUPPORT HAVING AT LEAST TWO CONTACT ELEMENTS ADAPTED TO ENGAGE TANGENTIALLY THE PERIPHERAL SIDE OF SAID RING UPON INWARD MOVEMENT OF SAID PLUNGER, SAID CURRENT-CONDUCTIVE RING BEING OPEN ENDED HAVING A DIAGONALLY-CUT SLOT AND ADAPTED TO BE COMPRESSED UPON ENGAGING SAID CONTACT ELEMENTS. 